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COMPOUND STEAM ENGINE. No. 448,001. Patented Mar. 10', 1891.

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J. BAIRD. COMPOUND STEAM ENGINE.-

No. 448,001. Patented Mar. 10,1891.

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UNITE STATES ATENT JOHN BAIRD, on NEW YORK, N. Y.

SPECIFICATION forming part of Letters Patent No. 448,001, dated March 10, 1891.

Application filed November 19, 1890- Serial No. 371,964. (No model.)

T0 at whom, it may concern.-

Be it known that 1, JOHN BAIRD, mechanical engineer, "a citizen of the United States, residing in New York city, county, and State, have invented certain new and useful Improvements in Compound Steam-Engines, of which the following is a specification.

My invention relates to the tandem class of compound engines, in which the steam-cylinders are arranged end to end in the same axial line; and its objects are to secure acompact, efficient, and simple organization which admits of the ready removal, replacement, or repair of the pistons and cylinder -heads. This also involves a reorganization of the valve-actuating mechanism. These ends I attain by a novel construction, combination, and organization of instrumentalities hereinafter specified.

My improvements, while useful in stationary engines, are especially adapted for use in locomotives, and are so shown in the accompanying drawings, which represent so much of a standard locomotive embodying the improvements herein claimed as is necessary to illustrate the subject-matter. Un-

, less otherwise indicated the parts are of usual well-known construction.

Figure 1 is a side elevation of alocomotive; Fig. 2, a plan of the cylinders and their appurtenant parts; Fig. 3, a side view of the same parts on a larger scale; Fig. at, a plan of the parts shown in Fig. 3; Fig. 5, a vertical central longitudinal section on the line 5 5 of Fig. 4:; Fig. 6, a rear view of a large cylininder and valve-chest with parts removed, and Fig. 7 a corresponding front view of a small cylinder and valve-chest.

A standard locomotive A is shown as pro vided with four coupled driving-wheelsB and a four-wheeled truck 0. Cylinders D E are secured on each side of the engine-frame over this truck in the same axial plane, the highpressure cylinders D being in front and directly connected in rear with the front heads of the low-pressure cylinder E. The pistons D E of each set of cylinders are connected by a piston-rod D passing through a stuffingbox at in the cylinder-head E In order to provide for the insertion and removal of the small piston .D, the front head D of its cylinder is made removable.

The piston-rod D is made tapering outwardly at both ends, its front end extending through a corresponding opening in the piston D and secured by a nut d, a recess (1 being left on the inner face of the head, into which the nut enters at the end of'its forward stroke. The rear end of this piston-rod is secured to the large piston E in a similar manner, except that the nut is countersunk fiush with the rear face of the piston. By removing the front head D and the nut d the piston D can be taken out at the front end of the cylinder D, whiqle the piston-rod can be withdrawn through the rear head. Each larger piston E is likewise connected in the way just described wit-h two pistonrods E arranged one over the other on each side of the central piston-rod D and, passing through stuffing-boxes e in the rear head or cover E the larger cylinder is removable at pleasure. The rear ends of the piston-rods E pass through cross-heads F, sliding in guides F on the frame, and are connected by pitmen G with the driving-wheels.

J am-nuts f f are secured on the pistonrods on each side of the cross-head to hold it securely, while admitting of its ready disconnection to facilitate the removal of the pistons'and the rear head E. The unscrewed part of the piston'rods are small enough to slide through the jam-nuts when unscrewed, so as to enable all the pistolrrods to be unscrewed from the piston and to be retracted through the head and out of its way. The removal of the head E is further facilitated by making the distance betwecn the vertically-arranged guides F greater than the diameter of the head, which latter is fitted when detached from the cylinder to slide upon these guides and yet can easily be removed therefrom. I

The cylinders being of different diameters and yet lying in the same axial line, their valve-chests must either lie in different planes or in the same plane. The latter construction involves the use of a valve at some distance from the cylinder, which causes a waste of steam at every stroke. I therefore prefer [O a link-motion L.

its rear head.

the former organizatioil, and this involves the working of the valves from opposite ends of their valve-chests, thus requiring a new organization of cross-heads and slides for 5 working them.

i5 lire-valve spindle, so that both sets of valves are simultaneously operated by the same linkmotion. This link-motion L and cross-head M are raised above the guides of the larger cylinder, so as not to obstruct the removal of The guides a", in which the rear cross-head M slides, are in fact shown as mounted on the valve-chests It and larger cylinders.

My invention contemplates the use of my apparatus in connection with the mosthighlyirnproved organizations of the present day. Its operation willreadily be understood from the foregoing description. Live steam flows from the boilers through a throttle-valve and 0 steam-pipes I to the high-pressure steamchest-s I and cylinders D, thence through a suitable receiver and heater(not shown) to the low-pressure steam-chests H and cylinders E after doing its work, in which it es- 3 5 capes into the smoke-pipe.

Having thus fully described my improved compound engine, what I claim therein as new and as of my own invention, is

1. The combination, substantially as hereinbefore set forth, of two abutting cylinders in the same axial line, pistons therein, a central piston-rod connecting both pistons, two additional piston-rods connected with the larger piston, the removable head of this larger piston, a cross-head with which these piston-rods are connected, an d guidesin which the piston-rods reciprocate and the removable cylinder-head slides and is supported when detached from its cylinder.

2. The combination, substantially as hereinbefore set forth, of the cylinder, its removable head, its piston, its two piston-rods, the guides for the cylinder and piston-rods, the cross-heads sliding therein, and the jam-nuts on opposite sides of the cross-head, through which and the jam-nuts when unscrewed the piston-rods slide to permit of the removal of the head and piston.

The combination, substantially as hereinbefore set forth,of the large and small cylinders in the same axial line, their valves in different planes, their rods or spindles, their cross-heads and slides at opposite ends of the valve-chests, the side rods connecting them, and the eccentric link-motion actuating both sets of Valves synchronously.

i. The combination, substantially as hereinbefore set forth, of the cylinders, their pistons and piston-rods, the cross-head, the vertical guides in which it slides, the valves, their cross-heads and side rods, the guides for the rear valve cross-head, mounted on the large cylinders and their valve'chests, and the eccentric link-motion actuating this valve cross-head.

In testimony whereof I have hereunto subscribed my name.

JOHN BAIRD.

Witnesses:

A. J. BAIRD, ADDISON XV. BAIRD. 

